Gripper for printing-presses



(No Model.)

GRIPPER FOR PRINTING PRESSES.

Patented July 29, 1890.

UNITED STATES PATENT OFFICE.

VILLIAM J. SHEA AND CORNELIUS BIRKERY, OF HARTFORD, CONNECTICUT.

GRIPPER FOR PRINTING-PRESSES.

SPECIFICATION forming part of Letters Patent No. 433,101, dated July 29, 1890. Application filed September 21, 1889. Serial No. 324,655. (No model.)

To all whom it may concern.-

Be it known that we, VILLIAM J. SHEA and CORNELIUS BIRKERY, both citizens of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Grippers for Printing lresses, of which the following is a full, clear, and exact specification.

The invention relates to the grippers used for temporarily holding to a feed-cylinder the paper which has been printed as it is fed to the folding mechanism of a printing-press; and the object is to provide a gripper which can be quickly and conveniently repaired when the finger becomes broken by the sub stitution of an inexpensive finger without removing the base of the gripper from its place on the gripper-shaft or disturbing the mechanism of the press.

Referring to the accompanying drawings, Figure l is a plan view of one of the cylinders of a printing-press provided with a nu mber of grippers. Fig. 2 is a top view, on enlarged scale, of one of the grippers. Fig. 3 is an edge view of the same with the base cut in central section. Fig. at is a front view of the base.

In the views, the letter a indicates the grippers that are secured to a shaft b, which is journaled in the ends of the cylinder 0, and provided on one end with a crank, which at the proper time during the rotation of the cylinder by contact with a cam secured to the frame oscillates the shaft and causes the fingers of the grippers'that project through an opening in the cylinder to grasp or release the paper.

These grippers are formed in two partsan annular base a, formed or cast of asoft, cheap, and tough metal, with a perforation a which fits the shaft, and an outwardly opening socket a in a part that projects from the annular base, and a hard spring-finger a, which is provided on its butt with a tongue a that fits the socket a in the base. The base a is slipped upon the shaft and permanently sccured in position by a set-screw d, which passes througha tapped socket in the base and abuts against the shaft, and the finger a is held firmly against movement in the socket a by a set-screw e, which passes through a tapped socket in the base and abuts against the tongue a. In order to prevent wear and insure a good grasp, these fingers have to be made very hard, and when quickly forced onto the paper against the cylinder to properly grasp and hold the paper these hardened fingers often break and have to be replaced, or the paper will fiy from the cylinder, roll into a wad, and clog the machine. Vhen one of the fingers is broken, the set screw e is loosened, the broken piece removed, and a new finger substituted without removing the base a or in any way disturbing its position or loosening its grasp on the shaft. The fingers are easily and cheaply struck from the proper metal and quickly placed in position, while the bases can be cast from a tough and less expensive metal with a perforation which just fits the shaft, so that they maybe firmly held in position by the set-screw.

As these grippers have previously been constructed, to replace a broken finger 11ecessitated the removal of the shaft from the cylinder, which could only be accomplished by taking out of the frame the driving-gears, the cams which operate the paper-guides and the cylinder, and by loosening the remaining fingers on the shaft. This oftenincapacitated the press at a critical time, as much skill and time are required to dissemble and assemble this mechanism and get it properly adjusted.

In the prior forms'of grippers, which are constructed so that it is not necessary to remove the shaft from the cylinder, the grippers have been attached to the shaft either by a setscrew in the base,as shown in patentto Tucker, of February 25, 187 9, or by a clamp and screw, as shown in patent to Hawkins, of March 22, 1887, and when one of the fingers of these grippers become broken an entirely new gripper has to be substituted, requiring careful adjustment upon the shaft each time a finger is broken.

The base of our improved gripper is not disturbed from its position on the shaft, and it does not depend 011 the binding effect of two pieces of metal held together on each side of the shaft, nor depend on the hold of a screw which passes through a more or less springarm which will give and loosen when the fingers close quickly.

In our-gripper the tongue on the butt of the finger fits and is firmly held against movement in a socket in the base, from which it can be easily and quickly removed, and as the Walls of the socket entirely surround the tongue, if the screw should by anymeans loosen, the finger will not swing around so as to be inoperative, while the base is practically permanently secured to the shaft.

We claim as our invention- A gripper for the cylinder of a printingpress, consisting of an annular base with a perforation fitting the gripper-shaft and an 

